I didn't mean that, I meant the boomerang going off the screen and not returning to Link at all. That is, not you dodging it as it reappears, but it completely disappearing after the initial forward through. I seem to remember it happening a few times, as well as in some videos I watched.
0:20 in this vid:
http://www.youtube.com/watch?v=PcjJAlS8lLk
Oh, that. Simply dash to the opposite direction you were facing when you threw the boomerang. It should be offscreen at the time it decides to stop and come back to you (if you still can see it when it tries to do so, it will not dissappear). But beware, if your enemy comes close to the point where you threw it (even if you dash to the opposite direction), it WILL come back, even if it was offscreen.
Thanks for the answer on the second question, can you clarify on this as well?
Standing: self-explanatory.
Crouching: self-explanatory.
Walking: the "boomerang catching" animation will not override a full-speed walk, but will to a "tilted" walk.
Fake boomerang throw: when you press B again too early, and nothing comes out of Link's hands.
Initial jumping animation: the time it takes for a character to lift off the ground after input (ironically Link takes the most time out of all the roster: 7 frames).
Doing nothing in air: self-explanatory. When I mentioned to be careful being off the ledge, I meant that this can "block" you from performing any standard/special move and will lock your horizontal speed and direction for a brief period of time (while the catching animation is in action), thus possibly ruining your recovery / being an easier target for an edgeguard. This happened to me several times, particularly before an UpB or a ledgehop.